Abstract
Background and Purpose:
Sleep hygiene is one factor that contributes to poor sleep in breast cancer survivors but is poorly measured. The purposes of this study were to (a) evaluate the psychometric properties of the Sleep Hygiene Awareness and Practice Scale (SHAPS) and (b) compare SHAPS scores between midlife women with and without breast cancer.
Methods:
Cross-sectional, descriptive data from a single-blinded, controlled hot flash intervention trial.
Results:
194 women (88 breast cancer survivors; 106 menopausal women). Reliability of the three sections of the SHAPS was inadequate with Cronbach’s alphas ranging from 0.23 to 0.67. Sleep hygiene practices were modestly correlated with global sleep quality in both groups.
Conclusions:
Findings suggest the SHAPS would need to be revised to be a psychometrically sound measure of sleep hygiene awareness and practice.
Keywords: sleep, sleep hygiene, symptom management, menopause, breast cancer, measurement
Inadequate sleep hygiene awareness and practices contribute to poor sleep. Sleep hygiene is defined as knowledge and practices that facilitate quality nighttime sleep and full-daytime alertness (American Academy of Sleep Medicine, 2005). Sleep hygiene practices can be variable and change over time because sleep behaviors change (Brown, Buboltz, & Soper, 2002). Examples of proper sleep hygiene include avoiding excessive daytime napping, caffeine use, and avoiding light exposure and strenuous exercise before bedtime. Inadequate sleep hygiene practices that contribute to poor sleep can also be related to prescription and over-the-counter sleep medication misuse and abuse. A recent survey found that 90% of American men and women watch television at least 1 hr before bed, which can contribute to insomnia symptoms (National Sleep Foundation, 2008). The survey also reported that 85% of respondents admitted to often misusing or abusing sleep aids to promote sleep (National Sleep Foundation, 2008). These findings are consistent with an increase in emergency room visits in 2010 related to prescription sleep medications, where menopausal women disproportionately reflected 67% of those cases (Substance Abuse and Mental Health Services Administration & Center for Behavioral Health Statistics and Quality, 2014).
In research studies, there are three standardized sleep hygiene questionnaires. Two instruments, the Sleep Hygiene Index (Cho, Kim, & Lee, 2013; Mastin, Bryson, & Corwyn, 2006) and Sleep Hygiene Self-Test (Blake & Gómez, 1998), both have been validated with moderate-to-low reliability (a 5 .54–.66). The third is the Sleep Hygiene Awareness and Practice Scale (SHAPS; Lacks & Rotert, 1986) that was constructed in 1986 to measure sleep hygiene knowledge and practices and tested among 93 adults with insomnia (Lacks & Rotert, 1986). The authors showed that those with insomnia had significantly poorer sleep hygiene awareness and practice (p , .05), with the exception of caffeine knowledge.
Psychometrics of the SHAPS has been evaluated in various populations such as adults with and without insomnia and college students (Brown et al., 2002) with variable reliability for the three sections (a 5 .47–.78; Brown et al., 2002). Responses to SHAPS items have been used to develop and tailor interventions for poor sleep and fatigue in breast cancer survivors (BCSs; Berger et al., 2009). However, psychometric properties of the SHAPS have not been fully evaluated in BCS or midlife women, limiting our understanding of how the questionnaire performs in this population. Because the SHAPS has been used previously in breast cancer studies, we selected it over the other measures of sleep hygiene that have not been used in cancer studies to determine if the reliability of the measure was adequate for further use. Therefore, purpose of this study was to evaluate the psychometric properties of the SHAPS and compare SHAPS scores between midlife women with and without cancer experiencing hot flashes.
METHOD
Design
Data for this cross-sectional, secondary data analysis came from women who had completed a randomized clinical trial for treating hot flashes (Carpenter et al., 2013). Women meeting inclusion criteria provided informed consent and approval to use health information before completing a baseline assessment and then were stratified and randomized into one of three groups. The SHAPS was completed at the end of the trial (16 weeks after intervention) after all of the parent trial procedures had been completed. Specific procedures of the parent study are published elsewhere (Carpenter et al., 2013). All procedures were approved by the Institutional Review Board and Cancer Center Scientific Review Committee. Informed consent was obtained for this study and adhered to the standards of privacy rights. SHAPS data collection occurred between May 7, 2009 and June 30, 2011.
Sample
Inclusion criteria for the parent study were adult females, reporting two or more hot flashes per 24-hr day of moderate or greater severity (≥ 4 using 0- to 10-point numeric rating scale) at initial screening, desirous of hot flash treatments, self-reported peri or postmenopausal status, in good general physical and mental health, no self-reported breathing difficulties, living within the local metropolitan area, and English literate. All BCS had to be at least 4 weeks postcompletion of surgery, radiation, and/or chemotherapy for nonmetastatic breast cancer and without a history of other cancers. The midlife women without cancer had to have no history of breast or other cancers (exception: basal cell skin carcinoma allowed). Recruitment was accomplished by (a) mass mailings to purchased mailing lists of women living in the community, (b) tumor registry participants, and (c) the Dr. Susan Love Research Foundation’s Love/Avon Army of Women research participant registry.
Measures
Self-reported demographics and health information collected at baseline in the parent trial were used in this analysis. The SHAPS was completed after all requirements of the parent study had been met.
The SHAPS is a measure of awareness of sleep practices and sleep behaviors developed in 1986 to assess the sleep hygiene behaviors of adult insomniacs to develop an intervention for improved sleep quality (Lacks & Rotert, 1986). Conceptually, the authors hypothesized that those with insomnia would have more awareness or knowledge of behaviors, foods, and drugs that contribute to poor sleep but that insomniacs are less likely to apply this knowledge to actual behaviors performed to enhance good sleep (Lacks & Rotert, 1986). The SHAPS includes three separate sections (Lacks & Rotert, 1986). Section 1 (sleep hygiene awareness) assesses the awareness of 12 items that negatively impact sleep using Likert-type responses (1 5 very beneficial, 2 5 moderately beneficial, 3 5 mildly beneficial to sleep, 4 5 no effect on sleep, 5 5 mildly disruptive, 6 5 moderately disruptive, 7 5 very disruptive). Higher scores suggest a higher awareness of behaviors and actions that negatively impact sleep. Section 2 tests the knowledge of 17 drinks, foods, and drugs that may or may not contain caffeine. Participants circle yes/no to endorse if the item contains caffeine. The higher the percentage of correct responses suggests higher knowledge of the negative impact of the food or drug on sleep. Section 3 (sleep hygiene practices) evaluates the number of nights (zero–seven) per week; an individual practices 19 activities that positively or negatively impact sleep. Higher scores indicate increased number of negative practices that can lead to poor sleep.
Data from the Pittsburgh Sleep Quality Index (PSQI) completed at the final visit for the parent study were used in the analysis. The PSQI evaluates self-reported sleep quality over the past month. The PSQI is the most commonly used questionnaire for the assessment of self-reported sleep quality in studies of BCS (Berger et al., 2009; Berger et al., 2003; Carpenter & Andrykowski, 1998; Carpenter et al., 2013; Otte et al., 2015). The PSQI was created to capture sleep quality in a sample of psychiatric patients. The PSQI is scored as 7 individual subscales and a single factor global score. The global score of the PSQI has been considered a measure for use in research to identify good versus poor sleep. The PSQI global sleep quality score has reported acceptable reliability in BCS (a 5 .80) and noncancer (a 5 .83) populations as well as validity (Buysse, Reynolds, Monk, Berman, & Kupfer, 1989; Carpenter & Andrykowski, 1998). Responses from 19 items generate seven subscale scores: sleep quality, sleep latency, sleep duration, sleep disturbance, sleep medication, daytime sleep, and sleep efficiency. A cutoff score greater than 5 indicates poor sleep quality (Buysse et al., 1989).
Data Analysis
The original scoring of the SHAPS is as follows. For Section 1, regarding sleep hygiene awareness, responses are given 1 point if correct, 2 points if omitted, and 3 points if incorrect. The range of scores is 13–36, with higher scores indicating less knowledge of sleep hygiene principles. For Section 2, responses are calculated based on the number of items answered correctly divided by the number answered resulting in scores that range from 0% to 100%. For the Section 3, responses are added for total possible scores, 0–133. Higher scores reflect worse sleep hygiene practices (Lacks & Rotert, 1986). After evaluating the questionnaire items, we revised the suggested scoring of Section 1 and Section 3 from the original article (Lacks & Rotert, 1986). In Section 1, Items 7, 8, 10, and 11 were reversed scored as in one previous study to better reflect how the items should be weighed in calculating the total score (Brown, Buboltz, & Soper, 2006). In Section 3, Items 16–19 were reversed scored because they promote good sleep hygiene and not poor practices. These recommendations for item reverse scoring were not addressed in the original article. Case summaries of the SHAPS items were conducted to detect missing items. There was less than 0.002% missing items noted on Sections 1–3 (11 responses total). Because there were little missing data, no mean imputation of missing items was conducted. Descriptive statistics (means and standard deviation for continuous variables, frequency and percentage for discrete variables) were used to describe the three sections of the SHAPS in addition to demographic characteristics in each group. Group differences on demographics, SHAPS item responses to Sections 1–3, and global sleep scores at baseline were compared using t tests, Wilcoxon scores, chi-square, and Fisher’s exact test analyses. Results were deemed significant if p , .05. The psychometric evaluation of the SHAPS sleep hygiene awareness (Section 1) and sleep hygiene practices (Section 3) was conducted using Cronbach’s alpha coefficients to examine internal reliabilities; item subtotal Pearson correlations; and Pearson correlation between Sections 1 and 3 of the SHAPS and PSQI global sleep scores. Confidence intervals were calculated using an established method that used the power calculations from the parent study (Feldt, Woodruff, & Salih, 1987). All analyses were done using Science Analysis System (SAS) Version 9.13 (Cary, NC, SAS Institute Inc.) and Statistical Package for the Social Sciences (SPSS) Version 21.0 (Armonk, NY, IBM).
RESULTS
Sample Characteristics
As shown in Table 1, breast cancer survivors were more likely to be White, be married, report no difficulty paying for basics, be nonsmokers, use selective estrogen receptor module or aromatase inhibitor (AI) and concurrent medications, and had more comorbid conditions as compare to menopausal women without cancer (p , .05). Other characteristics were not significantly different between groups.
TABLE 1.
Group Differences in Demographics
| Breast Cancer N = 88 |
Menopausal Women N = 106 |
||
|---|---|---|---|
| Background Characteristics | N (%) | N (%) | p |
| Ethnicity | 1.00 | ||
| Non-Latina | 87 (98.86) | 104 (98.11) | |
| Latina | 1 (1.14) | 2 (1.89) | |
| Race | <.00* | ||
| White | 78 (88.64) | 62 (58.49) | |
| Other | 10 (11.36) | 44 (41.51) | |
| Marital | .01* | ||
| Married/living with partner | 67 (76.14) | 60 (56.60) | |
| Single, widowed | 17 (19.32) | 42 (39.62) | |
| Other | 4 (4.55) | 4 (3.77) | |
| Employment | .58 | ||
| Full-time | 55 (62.50) | 70 (66.04) | |
| Part-time | 12 (13.64) | 17 (16.04) | |
| Not currently working | 21 (23.86) | 19 (17.92) | |
| Difficulty paying for basics | .00* | ||
| None | 76 (86.36) | 69 (65.09) | |
| Some | 10 (11.36) | 29 (27.36) | |
| A lot | 2 (2.27) | 8 (7.55) | |
| Smoker | .03 | ||
| Never | 65 (73.86) | 63 (59.43) | |
| Ever (former, current) | 23 (26.14) | 43 (40.57) | |
| Menopausal status | .25 | ||
| Early perimenopausal/late perimenopausal | 1 (1.18) | 4 (4.04) | |
| Early postmenopausal | 8 (9.41) | 15 (15.15) | |
| Late postmenopausal | 76 (89.41) | 80 (80.81) | |
| Use of SERM or AI | <.00* | ||
| Currently | 56 (63.64) | 2 (1.89) | |
| Not currently | 32 (36.36) | 104 (98.11) | |
| Background Characteristics | M (SD) | M (SD) | p |
|
| |||
| Age | 53.42 (8.36) | 52.75 (5.17) | .52 |
| Body mass index | 28.35 (5.79) | 29.29 (7.18) | .32 |
| Years of education | 15.38 (2.44) | 14.92 (2.23) | .17 |
| Number of concurrent medications | 2.84 (2.03) | 2.03 (2.00) | .01* |
| Number of comorbid conditions | 2.08 (1.05) | 1.46 (1.37) | .00* |
| Sleep Outcomes (Week 16) | M (SD) | M (SD) | p |
|
| |||
| Pittsburgh Sleep Quality Global Index Score | 7.49 (3.31) | 7.47 (3.53) | .96 |
Note. SERM 5 selective estrogen receptor module; AI 5 aromatase inhibitor.
p < .05.
Sleep Hygiene Knowledge and Practice
As shown in Table 2, BCS reported higher caffeine knowledge (Section 2) compared to midlife women (p 5 .0002), but no significant differences were found in general sleep hygiene awareness (Section 1) or sleep hygiene practices (Section 3). Not shown in Table is the fact that BCS had a higher awareness that sleeping the same length of time each night was beneficial to sleep (p 5 .004) in Section 1. More BCS correctly identified beverages that did not contain caffeine compared to midlife women without cancer (p , .05).
TABLE 2.
Descriptive Statistics and Internal Consistency Reliability
| Original scoring | Breast Cancer N = 88 | Menopausal Women N = 106 |
|---|---|---|
| Part 1: General sleep hygiene knowledge | ||
| Mean (SD) | 18.09 (3.52) | 19.32 (4.65) |
| Cronbach’s alpha | .47 | .67 |
| 95% Confidence interval | [.29, .62] | [.57, .76] |
| Part 2: Caffeine knowledge | ||
| Mean (SD): percentage correct | 80.48 (10.11) | 74.42 (11.28) |
| Part 3: Sleep hygiene practices | ||
| Mean (SD) | 30.05 (7.86) | 29.50 (9.17) |
| Cronbach’s alpha | .23 | .39 |
| 95% Confidence interval | [.02, .45] | [.21, .55] |
| Revised Scoring | ||
| Part 1: General sleep hygiene knowledge | 74.62 (14.68) | 69.42 (19.34)a |
| Part 3: Sleep hygiene practices | ||
| Mean (SD) | 21.59 (10.21) | 22.20 (10.33) |
| Cronbach’s alpha | .58 | .56 |
| 95% Confidence interval | [.44, .70] | [.43, .67] |
There was no change in the Cronbach’s alpha for the revised scoring of Part 1.
SHAPS Psychometrics
As shown in Table 2, Cronbach’s alphas were less than desired for an established scale (e.g., ,.80) in both groups.
We presented the item–subscale correlations for the SHAPS sleep hygiene awareness (Table 3) and sleep hygiene practices (Table 4). Item–subscale correlations for general sleep hygiene awareness ranged from r 5 .17 to r 5 .54 in the breast cancer group and r 5 .34 to r 5 .62 in no cancer menopausal women group. Moreover, item–subscale correlations for sleep hygiene practices ranged from r 5 .16 to r 5 .51 in the breast cancer group and r 5 .12 to r 5 .58 in no cancer menopausal women group.
TABLE 3.
Section 1: Sleep Hygiene Awareness of 12-Item–Subscale Correlations by Group
| Breast Cancer N = 88 | Menopausal Women N = 106 | |
|---|---|---|
| 1. Daytime napping | 0.32** | 0.34*** |
| 2. Going to bed hungry | 0.45*** | 0.46*** |
| 3. Going to bed thirsty | 0.47*** | 0.61*** |
| 4. Smoking more than one pack of cigarettes a day | 0.44*** | 0.52*** |
| 5. Using sleep medication regularly (prescription or over the counter) | 0.48*** | 0.34*** |
| 6. Exercising strenuously within 2 hr of bedtime | 0.39*** | 0.43*** |
| 7. Sleeping about the same length of time each night | 0.25* | 0.34*** |
| 8. Setting aside time to relax before bedtime | 0.17 | 0.49*** |
| 9. Consuming food, beverages, or medications containing caffeine | 0.50*** | 0.62*** |
| 10. Exercising in the afternoon or early evening | 0.25* | 0.38*** |
| 11. Going to bed at the same time each day | 0.22* | 0.48*** |
| 12. Drinking 3 oz of alcohol in the evening | 0.54*** | 0.51*** |
p < .05
p < .01
p < .001.
TABLE 4.
Section 3: Sleep Hygiene Practices of 19-Item–Subscale Correlations
| Breast Cancer N = 88 | Menopausal Women N = 106 | |
|---|---|---|
| 1. Taking a nap | 0.21* | 0.29** |
| 2. Going to bed hungry | 0.24* | 0.39*** |
| 3. Going to bed thirsty | 0.21* | 0.22* |
| 4. Smoking more than one packet of cigarettes per day | 0.27* | 0.29** |
| 5. Using sleeping medications (prescribed or over the counter) | 0.22* | 0.28** |
| 6. Drinking beverages containing caffeine within 4 hr of bed | 0.30** | 0.32*** |
| 7. Drinking more than 3 oz of alcohol | 0.20 | 0.13 |
| 8. Taking medications/drugs with caffeine within 4 hr of bed | 0.25* | 0.22* |
| 9. Worrying as you prepare for bed about your inability to fall asleep | 0.51*** | 0.58*** |
| 10. Worrying during the day about your inability to sleep at night | 0.32** | 0.54*** |
| 11. Using alcohol to help you sleep | 0.16 | 0.12 |
| 12. Exercising strenuously within 2 hr of bedtime | 0.28** | 0.16 |
| 13. Having your sleep disturbed by light | 0.47*** | 0.26** |
| 14. Having your sleep disturbed by noise | 0.38*** | 0.52*** |
| 15. Having your sleep disturbed by your bed partner’s sleep | 0.37*** | 0.29** |
| 16. Sleeping approximately the same length each night | 0.50*** | 0.47*** |
| 17. Setting aside time to relax before bedtime | 0.47*** | 0.43*** |
| 18. Exercising in the afternoon or early evening | 0.32** | 0.24* |
| 19. Having a comfortable nighttime temperature in bed and bedroom | 0.50*** | 0.43*** |
p < .05
p < .01
p < .001.
Correlations Between Sleep Hygiene Awareness and Practice Scale and Pittsburgh Sleep Quality Index Global Sleep Scores
The Sleep Hygiene Practice Scale (Section 3) was significantly correlated with global sleep scores in both groups: r 5 .41 (p , .05) in breast cancer group and r 5 .52 (p , .05) in the midlife women without cancer group, but no relationships were found between sleep hygiene awareness (Section 1) and global sleep scores in either group.
DISCUSSION
The psychometric strength of the three sections in the SHAPS among midlife women with and without cancer was not supported by this study because of the weak internal consistency–reliability of two sections in each group. The low Cronbach’s alphas are consistent with previous published results in other populations (Brown et al., 2002; Brown et al., 2006). Although the instrument performed slightly better in midlife women without cancer than women with breast cancer, the SHAPS would require revision to improve the overall performance of the scale for use in future research studies.
In addition, SHAPS items were not strongly correlated with overall sleep quality. The correlations between the SHAPS and PSQI global score were similar with one previous study (Brown et al., 2002). SHAPS Section 3 showed a moderate correlation with the PSQI, which was similar to a sample of university students (r 5 .49, p , .05). This finding suggests that what practices are conducted before bed can be correlated with the perception and reporting sleep quality. Our findings are also similar with one study that there is no relationship between PSQI global scores and sleep hygiene awareness section (Section 1; Brown et al., 2002). These findings could be explained, suggesting that what is known about practices that impact sleep does not directly correlate with how an individual actually self-reports sleep quality.
No significant differences were noted in the knowledge of sleep hygiene awareness section (Section 1) and sleep hygiene practices (Section 3) conducted during the week that negatively impact sleep. There were significant differences in the caffeine knowledge scale (Section 2), with BCS reporting more knowledge about three specific drinks that do not contain caffeine. However, confidence in these conclusions is tempered by the low performance of the scale, thus, the accuracy and generalizability of our findings to other populations is highly questionable.
There were several strengths of this study. The study provides new information about the reliability of the SHAPS in a group of BCS compared to women without cancer. The results of this study provide useful information regarding the need to further explore measurements of sleep hygiene in nursing research. Study findings should be considered in light of some limitations. The data findings are limited to women seeking treatment for hot flashes; however, postmenopausal hot flashes are a common phenomenon (.75%) in both BCS and midlife women (Conde et al., 2005). The sample size was relatively small and demographically limited. Repeating this analysis in larger and more diverse populations of midlife women should be considered.
In conclusion, although the standardized section scores are not recommended for use in research, evaluating the item responses from the SHAPS for both the sleep hygiene awareness (Section 1) and sleep hygiene practice (Section 3) can provide useful information for tailored interventions regarding what knowledge and actions need corrected to foster better sleep hygiene. However, a standardized questionnaire for sleep hygiene provides more opportunity to conduct in-depth statistical analysis such exploratory and confirmatory factor analysis to determine constructs of sleep hygiene knowledge and practices in a validated and reliable scale. It is recommended that focus groups be conducted in midlife women to assess how sleep hygiene is conceptualized and either create a new instrument specific to midlife women or revise the SHAPS.
Implications for Nursing Practice, Research, and Education
Nurses have an important role in the assessment and promotion of self-management of problems such as poor sleep. Integrating education regarding good sleep hygiene practices can reduce bad practices that hamper good sleep and improve overall sleep quality. To assess knowledge and practices, the SHAPS items can provide useful data to describe general sleep hygiene knowledge or practices in BCS. However, if the tool is to be used to use the current scoring to gauge severity of poor sleep hygiene knowledge and practices using the standardized scoring, the SHAPS would not be an appropriate tool because of the poor reliability in BCS. Further research would be needed to revise the tool to improve reliability of the standard scoring. For nursing education, the psychometric evaluation of the SHAPS can be integrated into a module of an evidence-based practice, undergraduate statistics course. Students can take the SHAPS questionnaire, enter the data into a statistical software program, and then conduct reliability testing, learning the essentials of instrumentation. The students can work in groups to discuss how to implement this work into practice.
Acknowledgments.
The project described was supported by Award Number R01CA132927. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute or the National Institutes of Health. The authors would like to acknowledge Dr. Debra Burns and Dr. Phyllis Dexter for their support of this manuscript.
Contributor Information
Julie L. Otte, School of Nursing, Indiana University, Indianapolis.
Jingwei Wu, Division of Biostatistics, Indiana University, Indianapolis.
Menggang Yu, Department of Biostatistics & Medical Informatics, University of Wisconsin, Madison.
Claire Shaw, School of Nursing, Indiana University, Indianapolis.
Janet S. Carpenter, School of Nursing, Indiana University, Indianapolis.
REFERENCES
- American Academy of Sleep Medicine. (2005). The international classification of sleep disorders: Diagnostic and coding manual (2nd ed.). Westchester, IL: Author. [Google Scholar]
- Berger AM, Kuhn BR, Farr LA, Lynch JC, Agrawal S, Chamberlain J, & Von Essen SG (2009). Behavioral therapy intervention trial to improve sleep quality and cancer-related fatigue. Psycho-Oncology, 18(6), 634–646. [DOI] [PubMed] [Google Scholar]
- Berger AM, VonEssen S, Kuhn BR, Piper BF, Agrawal S, Lynch JC, & Higginbotham P (2003). Adherence, sleep, and fatigue outcomes after adjuvant breast cancer chemotherapy: Results of a feasibility intervention study. Oncology Nursing Forum, 30(3), 513–522. [DOI] [PubMed] [Google Scholar]
- Blake DD, & Gómez MH (1998). A scale for assessing sleep hygiene: Preliminary data. Psychological Reports, 83(3 Pt. 2), 1175–1178. [DOI] [PubMed] [Google Scholar]
- Brown FC, Buboltz WC Jr., & Soper B (2002). Relationship of sleep hygiene awareness, sleep hygiene practices, and sleep quality in university students. Behavioral Medicine, 28(1), 33–38. [DOI] [PubMed] [Google Scholar]
- Brown FC, Buboltz WC Jr., & Soper B (2006). Development and evaluation of the Sleep Treatment and Education Program for Students (STEPS). Journal of American College Health, 54(4), 231–237. [DOI] [PubMed] [Google Scholar]
- Buysse DJ, Reynolds CF III., Monk TH, Berman SR, & Kupfer DJ (1989). The Pittsburgh Sleep Quality Index: A new instrument for psychiatric practice and research. Psychiatry Research, 28(2), 193–213. [DOI] [PubMed] [Google Scholar]
- Carpenter JS, & Andrykowski MA (1998). Psychometric evaluation of the Pittsburgh Sleep Quality Index. Journal of Psychosomatic Research, 45(1), 5–13. [DOI] [PubMed] [Google Scholar]
- Carpenter JS, Burns DS, Wu J, Otte JL, Schneider B, Ryker K, … Yu M (2013). Paced respiration for vasomotor and other menopausal symptoms: A randomized, controlled trial. Journal of General Internal Medicine, 28(2), 193–200. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cho S, Kim GS, & Lee JH (2013). Psychometric evaluation of the sleep hygiene index: A sample of patients with chronic pain. Health and Quality of Life Outcomes, 11, 213. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Conde DM, Pinto-Neto AM, Cabello C, Sá DS, Costa-Paiva L, & Martinez EZ (2005). Menopause symptoms and quality of life in women aged 45 to 65 years with and without breast cancer. Menopause, 12(4), 436–443. [DOI] [PubMed] [Google Scholar]
- Feldt LS, Woodruff DJ, & Salih F (1987). Statistical inference for coefficient alpha. Applied Psychological Measurement, 11(1), 93–103. [Google Scholar]
- Lacks P, & Rotert M (1986). Knowledge and practice of sleep hygiene techniques in insomniacs and good sleepers. Behaviour Research and Therapy, 24(3), 365–368. [DOI] [PubMed] [Google Scholar]
- Mastin DF, Bryson J, & Corwyn R (2006). Assessment of sleep hygiene using the Sleep Hygiene Index. Journal of Behavioral Medicine, 29(3), 223–227. [DOI] [PubMed] [Google Scholar]
- National Sleep Foundation. (2008). Sleep report card. Retrieved from http://sleepfoundation.org/sleep-report-card [Google Scholar]
- Otte JL, Carpenter JS, Manchanda S, Rand KL, Skaar TC, Weaver M, … Landis C (2015). Systematic review of sleep disorders in cancer patients: Can the prevalence of sleep disorders be ascertained? Cancer Medicine, 4(2), 183–200. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Substance Abuse and Mental Health Services Administration & Center for Behavioral Health Statistics and Quality. (2014). The DAWN Report: Emergency department visits for adverse reactions involving the insomnia medication zolpidem. Rockville, MD: Author. [PubMed] [Google Scholar]